Statistical Process Control Applied at Level Crossing Incidents

Given the increased importance of accidents at level crossing (LC) and the enormous damage caused by these accidents, it will be useful to question the safety measures at LC. Different scenarios are studied to compare the performance of control charts (CC) for detecting upward shifts of the quotient between the magnitude X and the time between events (TBE) which corresponds to a process’s deterioration: TBE distribution is exponential and for X two situations were retained (normal and Gamma distribution). The database covering the period 2009-2018 is obtained from the Tunisian railway company and the objective is to specify the best CC to monitor the situation at LC’s. The T distribution CC alone as well as that relative to X distribution alone does not make it possible to detect overruns and therefore does not lead to effective control of the situation at the LC. Unlike some previous research, the CC corresponding to the quotient X & T also does not allow rapid detection of overshoots if T is considered exponential and X is assumed to be normal. The objective of setting up a CC that makes it possible to control the situation at the concerned LC is achieved in the case where T is exponential and X follows a gamma distribution. In this case, the CC corresponding to the quotient (Q) makes it possible to detect overshoots quickly

Effect of Inherent Anisotropy on Shear Strength Following Crushing of Natural Aqaba Subgrade Sand

Inherent anisotropy affects the overall shear strength of sand deposits. Soil inherent anisotropy was evaluated for pre-crushed Aqaba subgrade sand by deposition of soil grains onto an inclined surface. Crushing of Aqaba sand was induced by one-dimensional compression. Sand characteristic properties (mineralogical properties, grain size and crushing resistance strength) were determined by standard laboratory testing. Particle breakage factors and inter-particle void ratio were calculated from the initial and final gradations of the soil samples. Moreover, shear strength components for sand specimens were resolved. Inspection of the residual shear strength parameters showed an increase, where the amount of particle crushing increased regardless the level of the normal stress being applied. Furthermore, examining the effect of inherent anisotropy showed that a considerable amount of the dilation occurs when the particles tend to lie orthogonal to the horizontal plane regardless the extent of breakage

Correlation between the tribology of concrete and the rheology of the corresponding mortars

The present work aims to study the possibility of characterizing the pumpability of concrete from the rheology of the derived mortars, i.e. concrete mortar (CM) and concrete equivalent mortar (CEM). As concrete is a material that is heavier than mortar, it is better to carry out tests on mortar. To this end, two test campaigns are presented in this article; the first campaign concerns the formulation of admixed concrete based on two mineral additions, namely limestone fillers and blast furnace slag. The aim of this first campaign was to study the tribological behavior of the formulated concretes. In the second test campaign, the formulations of the mortars were derived from the formulations of the corresponding concretes. Afterwards, a rheological study was carried out on these mortars. Analysis of the results obtained showed that there is a good correlation between the developed concretes and their corresponding CEMs, with fairly high determination coefficients

Correlation between the tribology of concrete and the rheology of the corresponding mortars

The present work aims to study the possibility of characterizing the pumpability of concrete from the rheology of the derived mortars, i.e. concrete mortar (CM) and concrete equivalent mortar (CEM). As concrete is a material that is heavier than mortar, it is better to carry out tests on mortar. To this end, two test campaigns are presented in this article; the first campaign concerns the formulation of admixed concrete based on two mineral additions, namely limestone fillers and blast furnace slag. The aim of this first campaign was to study the tribological behavior of the formulated concretes. In the second test campaign, the formulations of the mortars were derived from the formulations of the corresponding concretes. Afterwards, a rheological study was carried out on these mortars. Analysis of the results obtained showed that there is a good correlation between the developed concretes and their corresponding CEMs, with fairly high determination coefficients

Performance of Asphalt Mixes Containing RAP

Using Reclaimed Asphalt Pavement (RAP) in asphalt mixes has become a common practice in many countries. Experience indicated that the recycling of asphalt pavements is very advantageous from different perspectives. Some of the advantages of utilizing RAP include conservation of asphalt and aggregate resources, conservation of energy and reduction in life-cycle cost. In spite of that, RAP has never been used in Jordan. In this study, the suitability of asphalt mixes using RAP was investigated. Two hot asphalt mixes were prepared following gradations recommended by the Ministry of Public Works and Housing (MPWH/ Jordan). Marshall mix design procedure was used to determine the optimum asphalt content. The first mix was composed of 100% fresh aggregate and virgin asphalt and the second mix was composed of 30% RAP and 70% fresh aggregates and virgin asphalt. Marshal stability, loss of Marshall Stability, water sensitivity, indirect tensile strength, dynamic creep and fatigue tests were performed on samples of the two mixes. Comparing the results of the conducted tests indicated that the use of RAP in Hot Mix Asphalt (HMA) was advantageous in all properties measured except for the fatigue test, where shorter fatigue life was observed. The mix containing RAP showed less reduction in both loss in stability and loss in indirect tensile strength, improved stripping resistance and better creep performance than the mixture with fresh aggregates. Therefore, it is preferred to use mixes containing RAP in highways, where fatigue is not the predominant distress type

Internet law

This paper aims to illustrate the basis of cyberspace law and its potential environment. Indeed, the laws governing the cyberspace are still premature at both national and international levels. This is due to the undefined nature of cyber borders that globalize the Internet in contradiction with the geographic borders. Hence, individual countries are losing part of their sovereignty as result of globalization of the internet to a point it is becoming a borderless space with no laws and regulations. This urges to agree on new international legislations to handle any acts that are not confined by geographical borders or any obstructing matters. Given the fact that the cyberspace does not have such boundaries, it is not realistic to stop all the activities of electronic crimes or other harmful activities. In addition, it is challenging to define viable means to face such threats by individuals, organizations or countries. It is believed that subjecting the internet to the law may contradict with freedom and democracy. Nonetheless, subjecting the internet to the law under democratic approach can result in an effective means for exchanging information and culture among people around the world. Although it is impossible to fully prevent the occurrence of cyberspace risks and predict the potential threats on the countries communication and information systems, this research provides answers to a number of questions on how to achieve the protection of public order, whether domestic or international, from criminal cyberspace threats. The research paper is divided into two sections as follows: 1. Legislative and regulatory framework of cyberspace Law. Sources of cyberspace La

Antibacterial Activity of Small Molecules Which Eradicate Methicillin-Resistant Staphylococcus aureus Persisters

The serious challenge posed by multidrug-resistant bacterial infections with concomitant treatment failure and high mortality rates presents an urgent threat to the global health. We herein report the discovery of a new class of potent antimicrobial compounds that are highly effective against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The compounds were efficiently synthesized in one-pot employing a cascade of Groebke-Blackburn-Bienayme and aza-Michael addition reactions. Phenotypic screening of the pilot library against various bacterial species including methicillin-sensitive and MRSA strains, has identified potent chemotypes with minimal inhibitory concentrations (MIC) of 3.125-6.25 mu g/ml. The most potent compounds were fast-acting at eradicating exponentially growing MRSA, with killing achieved after 30 min of exposure to the compounds. They were also able to kill MRSA persister cells which are tolerant to most available medications. Microscopic analysis using fluorescence microscope and atomic force microscope indicate that these compounds lead to disruption of bacterial cell envelopes. Most notably, bacterial resistance toward these compounds was not observed after 20 serial passages in stark contrast to the significant resistance developed rapidly upon exposure to a clinically relevant antibiotic. Furthermore, the compounds did not induce significant hemolysis to human red blood cells. In vivo safety studies revealed a high safety profile of these motifs. These small molecules hold a promise for further studies and development as new antibacterial agents against MRSA infections.This work was supported by the generous grants from the IsDB-Transformers Fund and the Research Funding Department, University of Sharjah, UAE (CoV19-0306)